# n = int(input())
# e = 1
# factorial = 1
# for i in range(1,n+1):
#     factoyial = factorial * i
#     e = e + 1/factoyial
# print(f"{e:.8f}")
# n = int(input())
# e_approx = 1  # 先初始化和为第一项 1
# factorial = 1  # 用于计算阶乘，初始值为1! = 1
# for i in range(1, n + 1):
#     factorial *= i  # 计算 i 的阶乘
#     e_approx += 1 / factorial  # 累加每一项
# print(f"{e_approx:.8f}")
# from math import factorial

# n = int(input())
# e_approx = 1
# factorial = 1
# for i in range(1,n+1):
#     factorial = factorial * i
#     e_approx = e_approx + 1/factorial
# print(f"{e_approx:.8f}")
#
# my_list = {1,2,3,4,5}
# # for i in my_list:
# #     print(i)
#
# index = 0
# while index < len(my_list):
#
# my_list = [21,25,21,23,22,20]
# my_list.append(100)
# for i in my_list:
#     print(i) #打印出来看一下
# my_list.extend([29,33,30])
# print(my_list)
# print(my_list[0])
# l = len(my_list)
# print(my_list[l-1])
# print(my_list)
#
# m = my_list.index(33)
# print(f'下标是：{m}')
#
# # l = len(my_list)
# # for i in my_list:
# #     print(i)
# index = 0
# while index < len(my_list):
#     b = my_list[index]
#     print(b)
#     index+=1

# my_list = [1,2,3,4,5,6,7,8,9,10]
# for i in my_list:
#     if my_list[i]%2 == 1
#
# s = "abc#4e"
# for i in s:
#     if i.isalpha():
#
#         print(i,end="")

# def can_conbine(m,n):
#     for char in m:
#         if char not in n:
#             return False
#     return True
#
# m = input()
# if not m.isalpha():
#     print("ERROR")
# else:
#     n = input()
#     if can_conbine(m,n):
#         print("FOUND")
#     else:
#         print("NOT FOUND")
# def can_conbine(m,n):
#     for char in m:
#         if char not in n:
#             return False
#     return True
# m = input()
# if not m.isalpha():
#     print("ERROR")
# else:
#     n = input()
#     if can_conbine(m,n):
#         print("FOUND")
#     else:
#         print("NOT FOUND")